Sorry for the noob question but I need to know what I'm getting into. I recently bought a '91 CRX DX with a '91 D16A6 in it. It ran great until I took it down to Texas World Speedway and it developed a bad knock. I might have it rebuilt but I am also considering an "upgrade" to a DOHC ZC or D16A8. I want to use my current tranny as it has a Quaife. What issues would I have with swapping in a DOHC ZC or D16A8?